class Student(object):
    def __init__(self):
        self.__male = True
    def __speak(sef):
        print('hello')
class GirlStudent(Student):
    def __init__(self):
        Student.__init__(self)
    def intro(self):
        Student._Student__speak(self)
        print('I am girl')
        
s1 = Student()
#print(s1.__male)
print(hasattr(s1,'__male'))
print(hasattr(s1,'_Student__male'))
print(s1._Student__male)

s1._Student__speak()


g1 = GirlStudent()
g1.intro()